Yes. The per-share award will be whatever the jury decides to give, divided by however many shares are outstanding on that date.
If the share count increases between now and then, most likely due to warrant exercise, the pie will be divided among whoever holds shares at that time.
Or the time since the share was purchased will be taken into account, for example, someone who has held the share for 10 or 12 years should be compensated more than someone who bought it for 5 years
No, that won't matter. The class is defined as:
All current holders of common stock in Freddie Mac as of December 7, 2021, or their successors in interest to the extent shares are sold after December 7, 2021 and before any final judgment or settlement (the “Freddie Common Class”)
The part about "or their successors in interest to the extent shares are sold after" means whoever doesn't own shares on the date of final judgment or settlement gets nothing, no matter how long they owned their shares for before that, while anyone who does own shares on that date gets that share of the award, regardless of when they bought.